The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The invention is related in general to well site equipment such as wireline surface equipment, wireline cables and the like.
A process of removing the plastic stretch from a cable by allowing contra-helical armor layers on the cable to seat properly is known as “seasoning” of the cable. Cables are often “seasoned” in order to minimize damage to the cable and provide accurate depth measurements.
A seasoning process can include a “pre-stress” operation accomplished by subjecting a cable in an ends-fixed condition to high stresses at elevated temperatures. By performing the pre-stress operation, plastic stretch is partially removed from the cable, which allows the armor to arrange itself on the cable core. A pre-stressed cable has to be further “broken-in” during the first couple of visits to the well site. The process of “breaking-in” is done by running cable into a well, while carrying a heavy tool string which is free to rotate. Running in speed during the seasoning process has to be much slower compared to that for the “seasoned” cable. Cables armored with galvanized steel armor undergo seasoning quite well, which is attributed to the properties of the galvanized steel armor package. On the other hand, alloy cables having smooth non-corrosive armor do not season.
Specifically, alloy armor has smooth, almost slick, properties which inhibit corrosion and allow the armor to slide around much more freely. Therefore, “seasoning” cannot be applied to alloy cables, creating a number of operational issues. Certain alloy cables are highly torque imbalanced which manifests itself through excessive rotation downhole and resulting in a stretch on the alloy armor cable that is higher than a galvanized steel armored cable. This torque imbalance may also create an issue with accurate depth measurement. Accordingly, the probability of bird caging of the alloy armor cable is higher than with galvanized steel armored cabled.
Taking this into account, well site operations with alloy cable are much more time consuming, as running in and pulling out of the hole has to be done at speeds much slower than that of galvanized armored cable.
It remains desirable to provide improvements in wireline cables and/or downhole assemblies.